And at least in my limited experience, the impact of master being broken is pretty big, and even bigger when you have multiple teams. Either you block master - leading to a lot less than those 1000 commits making it to master on that day - or continue merging in stuff, which causes the root cause of the master branch to become fuzzy - and if your reporting is not in order, that is, if the person who broke the build isn't told they did, it'll be a lot of "Who broke master?" and people looking at each other to find out who is going to look into it. That's not scalable.